Phonograph records are conventionally sold within cardboard storage jackets of square shapes having two cardboard pieces joined at three edges and open at a fourth edge to permit the record to be inserted into and pulled out of the jacket through an elongated slit. The cardobard is of a sufficient thickness to help prevent record breakage during the storage. Before being inserted into the jacket, the record is first inserted into an envelope or sleeve that also has only one open edge. By inserting the record with the open envelope edge positioned alongside one of the closed jacket edges, the stored record is enclosed so as to prevent atmospheric dust from accumulating on it. Paper or ordinary plastic film is normally used to make the storage envelope which is much more flexible than the cardboard jacket. Use of the envelope also eliminates wear on the record surfaces during insertion into the jacket and as the record is pulled out of the envelope. Since the envelope is much more flexible than the jacket, the envelope can be opened in a manner that permits record insertion with very little, if any, wear.
Paper and ordinary plastic film record envelopes create a static electrical charge on the record as it is inserted into or pulled out of the envelope. The charge created is greater for plastic film envelopes than for paper envelopes. However, paper envelopes tend to deposit pulp particles onto the record. Static electrical charge on the record retains the pulp particles as well as attracting dust accumulation from the atmosphere as the record is being used. Any static electrical charge on the record either due to its insertion into and pulling out of the envelope or due to any charge accumulated during use is usually concentrated in what is known as "hot spots" which attract and retain the greatest amount of the accumulation. During storage, neither the paper nor the ordinary plactic film envelope dissipate any of the accumulated static electricity on the record. Tests have shown that the static electrical charges which accumulate on the record can reach 8,000 volts or more. This high voltage collects and retains the paper particles and the dust which cause accelerated record wear during use as well as a loss of the record fidelity.